Well scraper



y 9, 1939- M. MILLER ET AL 2,157,493

WELL SCRAPER Filed April 29, 1938 3 Sheets-Sheet l May 9, 1939.

M. MILLER ET AL WELL SCRAPER Filed April 29, 1938 3 Sheets-Sheet 2 MayB, 1939. M. MILLER ET AL WELL SCRAPER Filed April 29, 1938 3 Sheets-Sheet 5 Patented May 9, 1939 UNITED STATES PATENT OFFlCE l WELL SCRAI'ER Melvin Miller and Leon N. Davis, Flushing, Mich.

Application April 29, 1938, Serial No. 205,111-

10 Claims.

the well so that oil may again flow freely from the well.

Another object of the invention is to provide 10 a well scraper having resilient scraping arms which have a tendency to spring outwardly radially of the well into position for engaging the walls of the well, means being provided for holding the scraping arms in a retracted position dur- 1 ing lowering of the device through the well casing and the restraining means for the scrapers being of such construction that, when the device reaches the bottom of the well, the restraining means may be moved to a releasing position and 20 allow movement of the scrapers to an extended position for use. I

It is another object of the invention to so form and mount the restraining means for the scrapers that, when the device is lowered to the bottom 25 of the well, a shaft or plunger constituting an element of the restraining means will make contact with the bottom of the well and a sleeve shifted upwardly from a position about the scrapers so that the resilient scrapers may spring out- 30. wardly into position-to have scraping engagement with the walls of the well.

It is a further object of the invention to provide latch means which will retain the sleeve and its shaft in a raised position after releasing the 35 scraping arm and thus prevent the sleeve from sliding downwardly to a position in which it will retract the scraping arm as the device is drawn upwardly for a scraping operation.

Another object of the invention is to so con- 40 struct the device that during downward movement through the well casing the free-ends of the scraping arms will be shielded and prevented from catching against obstructions which may have formed in the well casing.

45 It is another object of the invention to provide a device of this character which is of a simplified construction and. will be very strong and durable and capable of withstanding rough usage.

The invention is illustrated in the accompany- 5o ing drawings, wherein Figure 1 is a view showing the improved well scraper in side elevation and disposedin position for use in a well which is shown in section,

Figure 2 is a sectional view upon an enlarged 55 scale taken longitudinally through the scraper and showing the scraper in position for use within a well shown in section,

Figure 3 is a sectional view taken transversely through the scraper along the line 3--3 of Figure 2,

Figure 4 is a sectional view takenlongitudinally through the scraper with the scraping arms in a retracted position,

' Figure 5 is a sectional view taken along the line 5--5 of Figure 4, and

Figure 6 is a sectional view taken along the line 66 of Figure 4.

This improved well scraping device is'used for removing parafiin and the like. i which forms upon walls of an oil well 2 below the well casing 3 which extends in the'well from the top thereof and terminates in spaced relation to the bottom of the well. The device is'lowered through the well casing by means of a rope or wire cable 4 which has one end secured through an eye bolt 5, and referring to Figures 2 and 4, it will be seen that the eye bolt is swiveled through the head or' closure disk 6 at the upper end of a cylindrical body or casing l. A bearing 3 is provided about the inner end portion of the shank 9 of the eye bolt in order that the eye bolt may turn freely in the head 6 and thus prevent spinning movement from being imparted to the scraping device by turning of the rope or cable.

The cylindrical body or casing 1 consists of metal tubing of the pioper length and diameter and at its lower end this casing is closed by a plug or head It! which fits snugly into the casing and is firmly secured therein. A disk I l which is of appreciably greater diameter than the tubular casing is disposed against the lower end thereof where it is secured by screws 12 which, pass through openings formed in the disk and are screwed into threaded sockets l3 formed in the plug or head l0. A center passage or opening I4 is formed through the disk II and registers with an opening or passage I5 formed through the head It! centrally thereof, the openings I4 and I5 defining a bore through which a shaft l6 slidably passes. The lower end of the sh'aftor plunger I 6 carries an abutment block I! for engaging the bottom of the well 2 and the upper end portion of the shaft is formed into a reduced and threaded stem 16 which is screwed into'a coupling block 19. The coupling block is formed with a transversely extending passage 20 through which a cross bar or pin 2| passes, and in order to secure the crossbar, there has been provided a ball 22 which is disposed in the socket 23 into which the stem I8 is screwed. The ball engages in a notch or recess 24 formed midway the length of the cross bar or pin 2| and when the stem I8 is screwed tightly into the socket 23 the ball will be held in place within the recess 24 and the cross bar or pin 2! will be firmly held against rotary movement or longitudinal movement. The cross bar or pin projects from opposite sides of the coupling 19 and its end portions extend through slots 25 formed in diametrically opposed portions of the tubular casing I. This limits sliding movement of the shaft or plunger l6 and in addition prevents turning movement of the shaft l6 so that a notch or latch receiving recess 26 formedin the lower portion of the shaft or plunger will follow a predetermined path of travel into and out of position to receive the latch 21 which serves to releasably secure the shaft in the position shown in Figure 2. This latch 21 is slidably mounted in a pocket 28 formed in the plug or closure l9 and the stem 29 of the latch passes outwardly through an opening or passage 30 formed centrally of a plug 3| which is screwed into a threaded opening formed through the tubular casing close to the lower end thereof.

A spring 32 is disposed about the latch stem within the pocket 28 and urges the latch inwardly so that, when the latch receiving recess 26 is in registry with the inner end of the pocket 28, the latch will be moved" into the latch receiving recess and firmly but releasably hold the shaft or plunger in the raised position of Figure 2.

The scraping arms 33 and 34 are formed from strips of resilient metal and these arms are formed integralwith bands 35 and 36 which fit about the casing 'l and are firmly secured by a collar 31. The free ends of the scrapers are bent upwardly and serrated to provide two flanges,

as shown at 38, so that, when the scraping arms or strips are expanded for engagement with the walls of the well, the paraflln or other material I which has been deposited upon the walls of the well may be scraped off. Referring to Figure 3, it will be seen that the free-ends of the scrapers define a circular path so that all portions of the walls of the well will be scraped clean. While the free ends of the scrapers extend in a circular path, the scrapers 33 are in a higher plane than the scrapers 34. This makes it easy to scrape the paraflin loose. -While the device is being lowered into the well, the scrapers must be retained in a retracted position, and in order to do so, there has been provided a sleeve 39 which fits about the casing and the collar 31 and adjacent its upper end is formed with openings 40 to receive ends of the cross bar or rod 2|.

, Guards 4| formed from bowed strips of metal are secured against the casing I and spaced from each other circumferentially thereof. These guards project outwardly beyond the sleeve 39 and will serve to engage the inner surface of the well tube 3 and'act as guides, in case the well tube is of such' diameter that the device has sliding fit within the same. These guards will also serve to limit transverse movement'of the device'in the well tube and together with the disk ll prevent ends of the sleeve 39 from catching against foreign matter which may have adhered to the well tube.

when this well scraper is in use, a rope or wire cable is secured through the eye bolt and the device lowered into the well with the sleeve 39 and shaft or plunger Ii in the lowered position so that the sleeve will serve to retain the scrapers in .the

retracted position shown in Figure 4 and the shaft or plunger extend downwardly below the disk II in its extended position. The guards or bumpers 4| and the disk II will serve to guide the device during its downward movement and prevent ends ofthe sleeve from catching against obstructions, 5 such as crustations, which may have formed upon the inner surface of the tubing or well casing 3. Upon reaching the bottom of the well the block II will rest upon the well bottom and continued downward movement of the casing 1 will cause the scrapers to move outwardly from the lower end of the sleeve 39 and the resiliency of these scrapers will cause them to spread and engage walls of the well. This longitudinal movement of the casing l and the sleeve 33 relative to each other will continue until the recess 26 registers with the pocket 28 at which time the latch 21 will enter the recess 26 and firmly secure the shaft or plunger IS with the sleeve 39 in the raised position shown in Fig- .tance sufficient to bring the scraping arm in engagement with the lower end of the tube or casing 3, the rope or cable 4 may be slackened so that the weight of the device may return it to the bottom of the well and the upward movement then repeated so that additional scraping action will take place. After the device has been reciprocated in the bottom of the well a sufficient number of times to insure removal of all of the paraffin from the walls of the well, the device may be drawn upwardly through the well tube or casing to the top of the well where it will be detached from the rope or cable and after being thoroughly cleaned the stem 29 of the latch will be grasped and drawn outwardly to dislodge the latch from the recess 26 and allow the shaft or plunger to be drawn downwardly and restore the sleeve to the lowered position in which it will be disposed about the scraper. The device will then be again ready for use and in addition the sleeve will serve as a shield toprotect the scrapers. and prevent them from being bent out of shape by careless handling of the device.

Having thus described the invention, what is claimed as new is:

1. A well scraper comprising a body, scraping arms about said body, extending longitudinally thereof and normally extending outwardly therefrom for engagement with walls of a well, a member movable into and out of position to retain the scraping arms in a retracted position, guiding means projecting from said body for engaging walls of a well, means for moving said retainer to a releasing position adapted to be actuated by engagement with the bottom of a well, and releas able means for holding said retainer in its adjusted position with the scraping arms in their extended position.

2. A well scraper comprising a body, scrapers carried by said body and movable from a retracted position to an extended position for scraping engagement with walls of a well, a retainer encircling the body and slidable along said body into and out of position to engage about and hold said scrapers in a retracted position, guides carried by scraping arms disposed about the body and movable from a retracted position to an extended position in which they project radially from the body for engagement with walls of a well, a sleeve about said body slidable longitudinally thereof into and out of position to engage about the scrapers and hold the scrapers in a retracted position, a plunger slidable longitudinally in said body and havingits upper end connected with said sleeve and its lower portion projecting from the lower end of the body for engagement with the bottom of a well to shift the plunger and sleeve upwardly and release the scrapers, and a latch carried by said body for engaging said plunger and holding the plunger and sleeve in an adjusted position 'with the scrapers extended while drawing the well scraper upwardly out of a well.

4. A well scraper comprising a tubular body, means for suspending said body from lowering means, a head at the bottom of said body, scrapers carried by said body about the same and movable from a retracted position adjacent the body to an extended position for engagement with walls of a well, a sleeve for holding said scrapers in a retracted position slidable longitudinally of said body, a plunger extending through the head and slidable longitudinally in said body, and means rigidly connecting the upper end of said plunger with said sleeve.

5. A well scraper comprising a tubular body,

suspending means at the upper end of said body,

a head for the lower end of said body, said body being formed with longitudinally extending slots, scraping arms disposed about the body below the slot and. extending longitudinally thereof and movable from av retracted position adjacent the body to an extended position for scraping engagement with walls of a well, a sleeve about said body slidable longitudinally thereof into and out of position to engage about the scrapers and hold the same in a retracted position, a plunger slidable longitudinally of said body through the lower head thereof, and a cross bar carried by the upper end of said plunger and extending through,

the slot with its ends connected with said sleeve.

6. A well scraper comprising a bodyhaving slots formed longitudinally therein, a collar about said body below said slots, scrapers secured about said body by said collar, said scrapers extending longitudinally of the body toward the lower end thereof and being movable from a retracted position adjacent the body to an extended position for engagement with walls of a well, a plunger slidable longitudinally in said body and projecting from the lower end thereof for engagement with the bottom of a well, and a cross bar carried by the upper end of said plunger and extending outwardly through the slots of the body withits outer end engaging said sleeve to move the sleeve with the plunger.

7. A well scraper comprising a tubular body, a head for the lower end of said body, scraping arms about the body extending longitudinally thereof toward the lower end of the body and movable from a retracted position to an extended position,a retainer about said body slidable longitudinally thereof into and out of position to hold the scrapers in a retracted position, a plunger slidable through said head and extending longitudinally in said body, a cross bar carried by the upper end of said plunger and extending outwardly through slots in said body and connected with said sleeve to move the sleeye with the plunger, and a latch carried by said head and urged inwardly to engage the plunger and secure the plunger in a raised position.

8. A well scraper comprising a tubular body formed with longitudinally extending slots, a head for the lower end of said body, a disk at the lower end of said body of appreciably greater diameter than the body, scrapers disposed about said body and extending longitudinally thereof between the slots and the lower end of the body and movable from a retracted position adjacent the body to an extended position, a sleeve slidable longitudinally of said body from a raised scraping arms extending longitudinally of said body toward the lower end thereof and having their upper ends carried by a band extending about the body, a collar carried by said body and engaged about said ,band to secure the arms, said arms normally projecting from the body in ,an extended position for scraping,engagement with walls of a well, a collar about said body slidable longitudinally thereof into and out of position to engage about the arms and hold the arms retracted, and actuating means for said collar including a plunger slidable longitudinally of the body and proiecting beyond the lower end thereof for engagement with the bottom of a well. I

10. A well scraper comprising a body, scrapers extending longitudinally of the body and movable from a retracted position to an extended position, a retainer slidable longitudinally of the body into and out of position to hold the scrapers retracted, an actuating plunger for said retainer, a disk of greater diameter than said retainer mounted at the lower end of said body, and guides carried by the upper portion of the body and projecting radially thereof beyond said re- 

